Curriculum Vitae

Research Positions

05/2005

08/2001-05/2005

 08/2000-08/2001

 01/2000-07/2000
 

Associate Professor of Physics department at University of Chile.

Assistant Professor of Physics department at University of Chile.

 Postdoctoral Fellow at California Institute of technology, USA.

 Postdoctoral Fellow at Institute Non Lineaire de Nice, France.

Education

1997-1999



1994-1996
 

1990-1994

1984-1989

Ph. D. at University of Nice and Sophia Antipolis, Nice, France
 Thesis ''Instabilites de systemes quasi-reversible''
 (Quasi-reversible Instabilities), advisor Prof. Pierre Coullet.

 Master in Physics at University of Chile at Santiago, Chile
 Thesis :''Tiempo de vida de un estado metaestable''
 (Escape time of a metastable state), advisor Prof. Enrique Tirapegui.

 Bachelor in Physics at University of Chile at Santiago, Chile
 (Facultad de ciencias Físicas y matemáticas de la Universidad
 de Chile, Departamento de Físicas).

 Secondary to '' Liceo de Aplicacion'', Santiago, Chile.

Research Proyect

• Principal investigator of FONDECYT project 1090045, entitled "Chaoticon: the localized spatio-temporal chaos", (2009-2011).
• Principal investigator of Ring-Program ACT15, Dynamics, Singularities and Geometry of Matter out of Equilibrium (2006-2008).
• Principal investigator of FONDECYT project 1051117, entitled "Noise induces propagation of localizad pattern" (2005-2006).
• Principal investigator of FONDECYT project 1020782, entitled "Dynamics growth" (2003-2005).
• Principal investigator of ECOS-CONICYT program C03E07, entitled "Localized structures and non vareiational effects".
• Associated investigator of FONDAP grant 11980002, Center for advanced Interdisciplinary Research in Materials (CIMAT).
• Program of Inserción de cientificos chilenos of Andes Fundation, entitled "Dinámica de estructuras localizadas y teoría de sistemas dinámicos aplicada a problemas de transporte y mezclamiento en geofísica" (08/2001-08/2003).

Conference Organizing

• Localized states in Physics: A focused workshop (LSWorkshop), September 22-25,2008, Santiago, Chile
• Latin American Workshop on Nonlinear Phenomena (LAWNP 2007), October 29-Noverber 01, Arica, Chile.
• Southern Workshop on granular Materials 2003, December 10-13, Pucón, Chile (SWGM03).
• XIV Conference on Nonequilibrium Statistical Mechanics and Nonlinear Physics, December 6-10, La Serena Chile (MEDYFINOL04).
• Southern Workshop on granular Materials 2006, September 10-13, Viña del Mar, Chile (SWGM06).

Currently Referee

Guest Editor for special Issue

• Physica A, vol. 356, Issue 1 (2005).
  14th conference on Nonequilibrium statistical Mechanics and Nonlinear Physics.
• Theme section: Advances in Nonlinear Phenomena:
  International Journal of Bifurcation and Chaos 19, Issue 8 (2009).

  In my thesis for the degree of Master in physics directed by E. Tirapegui in the University of Chile, in Chile. I become familiar with study of non equilibrium systems and the methods of nonlinear physics. In my thesis, I did a theoretical study of the detailed balance in the frame of the mesoscopic description of macroscopic systems through a master equation. My approach was based in the notion of reversed Markov process and I was able to show that one can always put a Markov process with stationary probability in generalized detailed balance  adding a suitable set of odd parameters under time reversal transformation [1, 2]. I studied also the problem of the escape time due to noise from the basin of attraction of attractor (point, limit cycle and so on) and I found explicit formulas (when the non-equilibrium potential is differentiable) that  generalize the Kramer's rate.

  In my Ph. D. thesis done at "Institut Nonlineaire de Nice" at University of Nice-Sophia Antipolis (France), under the direction of Professor P. Coullet, I treat three different subject:

•  Instability of quasi-reversible system. Time reversible dynamical systems  present two generic spectral instabilities: The stationary instability or  resonance at zero frequency and the 1:1 resonance or confusion of  frequencies. I have studied systems in which the time reversal symmetry  is weakly broken in presence of a neutral mode through which energy is injected in the system. I have proved  that the normal form of the stationary instability when one has reflection symmetry is the set of real Lorenz  equations and the normal form of confusion of frequencies is the set of Maxwell-Bloch equations which describes the dynamic of two level atom in an optical cavity [3, 4, 8,10,14]. These two well know sets of equations turns out to be then universal equations. I have exhibited numerous examples of these situations. An interested system is a simple mechanical pendulum oscillating respect to a turning support submitted to a constant torque which displays Lorenz type chaotic behavior, which we have called Lorenz pendulum. We have also characterized the quasi reversal instability of periodical solutions [16].

• Appearance and dynamics of waves in a ring laser. Periodic and chaotic alternation of right and left traveling waves close to threshold appear to be the more robust dynamical behavior. A new set of amplitude equations which I derived from the Maxwell-Bloch equations explain the previous phenomena. I gave an analytic description of the mechanisms of alternation between waves [5,7].

•  Interface dynamics in the liquid crystal. In the framework of  nonlinear elastic theory of liquid crystals, I have derived an amplitude equation which is valid close to the Freederickz transition and I put in evidence the fundamental role of the elastic anisotropy. The interface is described by a conservative order parameter which satisfies the Cahn-Hilliard equation [6, 9,11,20], whose dynamics is characterized by coarsening of the vertices or bubbles. Three opposite facets (zig-zag-zig) form a bubble. For a gas of diluted bubbles  we have found an ordinary differential equations describing their interaction, which permits us to describe the ulterior dynamic of the system in a very good agreement with the experiment and numerical simulations [11]. From the amplitude equation, we have deduced for large anisotropy of elastic constant the Freederickz transition can becomes an spatial transition [19].

I was realized my first postdoctoral position in the Institute Non lineaire de Nice, between January and July, 2000. I was studied the effect of the self interaction of a nematic liquid crystal by mean of the optical feedback [12,13]. We were shown that the Freederick transition can become a first order type [15]. This result has different potential technological applications. Moreover, we have studied experimentally and theoretically the dynamics exhibits by the different front solutions and localized structure observed in this system, in particular close to the Freederick transition.

I was realized my second postdoctoral position in the California Institute of technology (CALTECH) between August 2000 and July 2001. I was characterized how the energy dissipation or damping in a quasi reversal system or quasi hamiltonian can induce instability. There are two fundamental linear instabilities for the Hamiltonian and time reversible systems, the stationary instability and 1:1 resonance. Spectral instability implies linearly instability, but linearly instability does not imply spectral instability. We have studied the dynamics and perturbations of systems that are gyroscopically stable. We call such situations Latent bifurcation since interesting physical perturbations can cause movements of eigenvalues across the imaginary axis. This bifurcation requires long time to manifest. A indication of this is the phenomenon denominated dissipation induced instability, that is, when one consider small dissipation effects the equilibrium becomes spectrally unstable. The latent bifurcation is a consequence of the fact a conservative quantitative becomes non definite at equilibrium, which allows that the equilibrium perturbations explore a larger region of phase space. Physical systems that exhibit this bifurcation are: Laser with slightly pumping (active medium), Baroclinic instability, simple mechanic systems (Double spherical pendulum that is the mechanical analogous of the laser), movement of planets in Celestial mechanics, intra-molecular dynamics [17].

I am assistant professor of Physics Department of University of Chile, from August 2001. My scientific efforts have been supported by Inserción de científicos chilenos de fundación Andes, Fondecyt grant 1020782 and FONDAP grant 11980002.

In the frame of the Fondecyt grant 1020782 entitle Dynamics growth and ECOS program of cooperation Franco-Chilean, I was kept my collaboration with the group of liquid crystal and nonlinear optic in the Nonlinear Institute of Nice, France. I realized periodic visit to this laboratory, one month by year. We have continued studying the rich dynamic behavior observed in the liquid crystal light valve with optical feedback. In particular, we achieved to characterize experimentally and theoretically the front speed observed close to Freederickz transition [18,23,25]. Far from this transition, we observe a permanent dynamic of localized structures. From first principles, we have derived an amplitude equation, Lifshitz normal form, which is non-variational and gives account of the periodic and chaotic behavior of the localized structures [26,28].

I am associated investigator of FONDAP 11980002, CENTRO INTERDISCIPLINARIO DE ESTUDIOS DE MATERIALES (CIMAT), from 2002. Inside this center, we have developed the research area of non linear behavior of granular matter out of equilibrium. We have shown that fluidized granular matter exhibits a phase separation [21,22,24]. Molecular dynamics simulations of grain system, in two spatial dimensions, with a vibrating wall and without gravity exhibit appearance, coagulation and disappearance of bubbles, that is, the system shows coexistence of two different fluidized states (with dissimilar density). We have identified the physical mechanism responsible of phase separation and show that the phenomenon is analogous to the spinodal decomposition of the gas-liquid transition of the classical van der Waals model [21,22,24]. In the onset of phase separation, we have deduced a macroscopic model, a van der Waals normal form, which agrees quite well with molecular dynamics simulations. From this model, we have described and deduced the bubbles interaction, which is governed by densification waves, solitary, rarefaction and shock waves, that is, this nonlinear wave are responsible of the coarsening dynamics observed in this system. From a one dimensional hydrodanamic model that minic the dynamic in two dimension we have deduced the van der waals normal form [27].

1.  ''Detailed balance in Markov process'' Instabilities and Non equilibrium structures V, eds. E. Tirapegui and W. Zeller (with F. Barra, C. Huepe,   E. Tirapegui), Kluwer(1996).
2. "Reversed process and detailed balance'' (with F. Barra, E. Tirapegui), Dynamics and stability of Systems, 12, 61 (1997).
3. ''Lorenz Pendulum and Poincar chaos'' (with P. Coullet, J.M. Gilli,  E. Tirapegui,and N. Vandenberghe) Des Phenom nes Critiques au    Chaos (Ed. by CEA direction des Sciences de la Matiere, Saclay 1998).
4. ''The Maxwell-Bloch description of 1/1 resonances'' (with P. Coullet,    E.Tirapegui) Optical Communications 167, 159 (1999).
5. '' Dynamique bidirectionnelle dans le laser en anneau''(with P. Coullet) Rencontre du non-lineaire 1999, 167-112, Eds. Y. Pomeau and  R. Ribotta (Paris Onze Editions, Orsay 1999).
6. ''Instabilite zig-zag d'une paroi d'ising dans les cristaux liquides''(with C. Chevallard, P. Coullet, J. M. Gilli) Rencontre du non-lineaire 1999, 203-207, Eds. Y. Pomeau and R. Ribotta (Paris Onze editions, Orsay 1999).
7. ''Chaotic Alternation of Waves in Ring Lasers'' (with P. Coullet) Phys.  Rev. E 60, 6589 (1999).
8. '' Lorenz Bifurcation: Instabilities in Quasi-reversible Systems''(with P. Coullet, E Tirapegui) Phys. Rev. Lett. 83, 3820 (1999).
9. ''Interface dynamics in Liquid crystals'' (with C. Chevallard, P. Coullet,   J. M. Gilli) Eur. Phys. J. E 1, 179 (2000).
10. ''Reduced description of the confined quasi-reversible Ginzburg    Landau equation'' (with P. Coullet, E. Tirapegui) Progress of    Theoretical Physics Supplement, 139, 337-343 (2000).
11. ''Bubbles interaction in Canh-Hilliard equation'' (with H. Calisto, R.    Rojas, E. Tirapegui) Physical Review Letters 85, 3805 (2000).
12. ''Dynamiques des cristaux liquides sous retro-injection optique''(with    P. Coullet, C. Riera) Rencontre du non-lineaire 2000, 257-260, Eds. Y.  Pomeau and R. Ribotta (Paris Onze Editions, Orsay 2000).
13. "Transition de Freedericksz du premier ordre dans un cristal liquide nematique et en pr sence d'une retroaction optique.''(with S. Residori, C. Riera) Rencontre du non-lineaire 2001, 231-236, Eds. Y. Pomeau and R. Ribotta (Paris Onze Editions, Orsay 2001).
14. ''The stationary instability in quasi-reversible systems and the Lorenz    pendulum'' (with P. Coullet, E. Tirapegui)  International Journal of Bifurcation and Chaos 11, 591-603 (2001).
15. ''First-Order Freedericksz transition in the presence of a light driven feedback'' (with S.Residori, C. Riera) Phys. Rev. E 63, 060701 (2001).
16. "Quasi-Reversible instabilities of closed orbits'' (with P. Coullet, N.Vandenberghe, E. Tirapegui) Phys. Lett. A 287. 198-204 (2001)
17. "Dissipation-induced insatability in an optical cavity laser: A mechanical analog near the 1:1 resonance'' (with Jerrold E. Marsden), Phys. Rev. E 64, 067603 (2001).
18. " First Order Freedericksz Transition in a Liquid-Crystal-Light -Valve ", (with T. Nagaya, S. Residori, C.S. Riera) Conference Proceedings f the 6th Experimental Chaos Conference (Postdam, 21-26 July 2001).
19. "Inhomogeneous Freederickz transition in nematic liquid crystal'' (with C. Chevallard) Phys. Rev. E 65, 011708 (2002).
20. "Zig-Zag instability of Ising wall in liquid crystal'' (with C. Chevallard, P.Coullet, J. M. Gilli) Europhysics Lett. 58, 686-692 (2002).
21. "van der Waals-like transition in fluidized granular matter" (with M. Argentina, R. Soto) Physical Review Letters 89, 044301 (2002).
22. '"van der Waals-like Transition in Fluidized Granular Matter: Hydrodynamic description" (with M. Argentina, R. Soto) Kinetic theory of Granular Gases, edited by T Pschel and N. Brilliantov, Lecture Notes in Physics, Vol. 624 (Springer, Berlin 2003).
23. " Front dynamics in Liquid CrystalLight Valve with feedback", (with A. Petrossian, S. Residori, C.S. Riera ) Instabilities and Non equilibrium structures IX, eds. O. Descalzi, S. Rica. J. Martinez, Kluwer (2004).
24. '"van der Waals-like Transition in Fluidized Granular Matter: Hydrodynamic description" (with M. Argentina, R. Soto) Instabilities and Non equilibrium structures IX, eds. O. Descalzi, S. Rica. J. Martinez, Kluwer (2004).
25. "First-Order Fréedericksz Transition and Front Propagation in a Liquid Crystal Light Valve with Feedbac" (with T. Nagaya, A. Petrossian, S.Residori, C. Riera) Eur. Phys. J. D 28, 435 (2004).
26. "Localized Structures and their Dynamics in a Liquid-Crystal-Light-Valve with Optical Feedback" (with S.Residori, A. Petrossian and T. Nagaya) J. Opt. B: Quantum Semiclass. Opt. 6, S169 (2004).
27. "van der Waals normal form for a one-dimensional hydrodynamic model'' (with C. Cartes and R. Soto) Phys. Rev. E 70, 031302 (2004).
28. "Fronts and localized structures in a Liquid-Crystal-Light-Valve with optical feedback'' (with S.Residori, A. Petrossian, T. Nagaya, C. Riera) Physica D 199, 149-165 (2004).
29. "Bouncing localized structures in a Liquid-Crystal-Light-Valve experiment" (with S.Residori, and A. Petrossian) Phys. Rev. E 171, 015205-1 (2005).
30. "Additive noise induces Front propagation'' (with C. Falcon, E. Tirapegui,) Physical Review Letters 94, 148302 (2005).
31. "Dynamics of one-dimensional Cahn-Hilliard model.'' (with M. Argentina, R. Rojas, E. Tirapegui) Phys. Rev. E 71, 046210- (2005).
32. "Localized patterns and hole solutions in one-dimensional extended systems" (with C. Falcon), Physica A 356, 48 (2005).
33. "Patterns and localized structures in population dynamics" (with D. Escaff, and V. M. Kenkre) Phys. Rev. E 72,056217 (2005)
34. "Localized states in bistable pattern forming systems" (with U. Bortolozzo, C. Falcon, S. Residori, and R. Rojas) Physical Review Letters 96, 214501 (2006).
35. "Front propagation sustained by additive noise" (with C. Falcon, E. Tirapegui) Phys. Rev. E 74, 011303 (2006).
36. "Solitary waves in van der Waals-like transition in fluidized granular matter", (with D. Escaff) Physica A 371, 33 (2006).
37. "Pattern Formation and Localized Structures in Reaction-Diffusion Systems with Non-Fickian Transport", (with M. Trejo and E. Tirapegui) Phys. Rev. Letts. 97, 176102 (2006).
38. " Noise induced rolls propagation", (with D. Escaff, C. Falcon and E. Tirapegui) The European Physical Journal - Special Topics. 143, 171-179 (2007).
39. "Pattern formation and localized structures in monoatomic layer deposition", (with E. Tirapegui & M. Trejo) The European Physical Journal - Special Topics. 146, 407-426 (2007).
40. Comment on "Asymptotics of Large Bound States of Localized Structures", (with C. Falcon and E. Tirapegui) Phys. Rev. Lett. 100, 049401 (2008).
41. "Universal shape law of stochastic supercritical bifurcations: Theory and experiments", (with Gonzague Agez, and Eric Louvergneaux) Phys. Rev. E 77, 026218 (2008).
42. "Liquid-solid-like transition in quasi-one-dimensional driven granular media", (with P. Cordero, J. Dunstan, K. Huff, N. Mujica, D. Risso & G. Varas) Nature Physics, 4, 249-254 (2008).
43. "Localized states beyond asymptotic parametrically driven amplitude equation", (with S. Coulibaly and D. Laroze) Phys. Rev. E 77, 056209 (2008).
44. "Transversal interface dynamics of a front connecting a stripe pattern to a uniform state" (with Daniel Escaff and Rene Rojas), Europhys. Lett. 83, 28002 (2008).
45. "Shilnikov bifurcation: Stationary quasi-reversal bifurcation ",
    (with P. Encina, and E. Tirapegui) International Journal of Bifurcation and
    Chaos 18, 1905 - 1915 (2008).
46. "Local theory of the slanted homoclinic snaking bifurcation diagram ", (with U. Bortolozzo, and S. Residori ) Phys. Rev. E 78, 036214 (2008).
47. "Localized States in Bi-Pattern Systems",
    (with U. Bortolozzo, F. Haudin, R.G. Rojas, and S. Residori )
    Advances in Nonlinear Optics 926810 (2009).
48. "Soliton pair interaction law in parametrically driven Newtonian fluid",
    (with S. Coulibaly, N. Mujica, R. Navarro, and T. Sauma)
    Phil. Trans. R. Soc. A 367, 3213-3226 (2009).
49. "Driven Front Propagation in 1D Spatially Periodic Media",
    (with F. Haudin, R.G. Elías, R.G. Rojas, U. Bortolozzo, and S. Residori)
    Phys. Rev. Lett. 103, 128003 (2009).
50. "Solitary localized structures in a liquid crystal light-valve experiment"
    (with U Bortolozzo and S Residori)
    New J. Phys. 11, 093037 (2009).
51. "Non-variational Ising-Bloch transition in parametrically driven systems"
    (with S. Coulibaly and D. Laroze), International Journal of Bifurcation and Chaos 19, 2717-2726 (2009).
52. "Dynamics of an interface connecting a stripe pattern and a uniform state: Amended Newell-Whitehead-segel equation"
    (with R. Rojas, and R.G. Elias)
    International Journal of Bifurcation and Chaos 19, 2801-2812 (2009).
53. "Parametrically driven instabilities in quasi-reversal systems",
    (with S. Coulibaly and D. Laroze),International Journal of Bifurcation and Chaos 19, 3525-3532 (2009).
54. "Localized states of parametrically driven easy-plane ferromagnetic wire"
    (with S. Coulibaly and D. Laroze), Physica D 239, 72 (2010).